diff options
Diffstat (limited to 'Documentation/devicetree/bindings/xilinx.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/xilinx.txt | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/xilinx.txt b/Documentation/devicetree/bindings/xilinx.txt new file mode 100644 index 000000000..28199b31f --- /dev/null +++ b/Documentation/devicetree/bindings/xilinx.txt @@ -0,0 +1,165 @@ + d) Xilinx IP cores + + The Xilinx EDK toolchain ships with a set of IP cores (devices) for use + in Xilinx Spartan and Virtex FPGAs. The devices cover the whole range + of standard device types (network, serial, etc.) and miscellaneous + devices (gpio, LCD, spi, etc). Also, since these devices are + implemented within the fpga fabric every instance of the device can be + synthesised with different options that change the behaviour. + + Each IP-core has a set of parameters which the FPGA designer can use to + control how the core is synthesized. Historically, the EDK tool would + extract the device parameters relevant to device drivers and copy them + into an 'xparameters.h' in the form of #define symbols. This tells the + device drivers how the IP cores are configured, but it requires the kernel + to be recompiled every time the FPGA bitstream is resynthesized. + + The new approach is to export the parameters into the device tree and + generate a new device tree each time the FPGA bitstream changes. The + parameters which used to be exported as #defines will now become + properties of the device node. In general, device nodes for IP-cores + will take the following form: + + (name): (generic-name)@(base-address) { + compatible = "xlnx,(ip-core-name)-(HW_VER)" + [, (list of compatible devices), ...]; + reg = <(baseaddr) (size)>; + interrupt-parent = <&interrupt-controller-phandle>; + interrupts = < ... >; + xlnx,(parameter1) = "(string-value)"; + xlnx,(parameter2) = <(int-value)>; + }; + + (generic-name): an open firmware-style name that describes the + generic class of device. Preferably, this is one word, such + as 'serial' or 'ethernet'. + (ip-core-name): the name of the ip block (given after the BEGIN + directive in system.mhs). Should be in lowercase + and all underscores '_' converted to dashes '-'. + (name): is derived from the "PARAMETER INSTANCE" value. + (parameter#): C_* parameters from system.mhs. The C_ prefix is + dropped from the parameter name, the name is converted + to lowercase and all underscore '_' characters are + converted to dashes '-'. + (baseaddr): the baseaddr parameter value (often named C_BASEADDR). + (HW_VER): from the HW_VER parameter. + (size): the address range size (often C_HIGHADDR - C_BASEADDR + 1). + + Typically, the compatible list will include the exact IP core version + followed by an older IP core version which implements the same + interface or any other device with the same interface. + + 'reg' and 'interrupts' are all optional properties. + + For example, the following block from system.mhs: + + BEGIN opb_uartlite + PARAMETER INSTANCE = opb_uartlite_0 + PARAMETER HW_VER = 1.00.b + PARAMETER C_BAUDRATE = 115200 + PARAMETER C_DATA_BITS = 8 + PARAMETER C_ODD_PARITY = 0 + PARAMETER C_USE_PARITY = 0 + PARAMETER C_CLK_FREQ = 50000000 + PARAMETER C_BASEADDR = 0xEC100000 + PARAMETER C_HIGHADDR = 0xEC10FFFF + BUS_INTERFACE SOPB = opb_7 + PORT OPB_Clk = CLK_50MHz + PORT Interrupt = opb_uartlite_0_Interrupt + PORT RX = opb_uartlite_0_RX + PORT TX = opb_uartlite_0_TX + PORT OPB_Rst = sys_bus_reset_0 + END + + becomes the following device tree node: + + opb_uartlite_0: serial@ec100000 { + device_type = "serial"; + compatible = "xlnx,opb-uartlite-1.00.b"; + reg = <ec100000 10000>; + interrupt-parent = <&opb_intc_0>; + interrupts = <1 0>; // got this from the opb_intc parameters + current-speed = <d#115200>; // standard serial device prop + clock-frequency = <d#50000000>; // standard serial device prop + xlnx,data-bits = <8>; + xlnx,odd-parity = <0>; + xlnx,use-parity = <0>; + }; + + That covers the general approach to binding xilinx IP cores into the + device tree. The following are bindings for specific devices: + + i) Xilinx ML300 Framebuffer + + Simple framebuffer device from the ML300 reference design (also on the + ML403 reference design as well as others). + + Optional properties: + - resolution = <xres yres> : pixel resolution of framebuffer. Some + implementations use a different resolution. + Default is <d#640 d#480> + - virt-resolution = <xvirt yvirt> : Size of framebuffer in memory. + Default is <d#1024 d#480>. + - rotate-display (empty) : rotate display 180 degrees. + + ii) Xilinx SystemACE + + The Xilinx SystemACE device is used to program FPGAs from an FPGA + bitstream stored on a CF card. It can also be used as a generic CF + interface device. + + Optional properties: + - 8-bit (empty) : Set this property for SystemACE in 8 bit mode + + iii) Xilinx EMAC and Xilinx TEMAC + + Xilinx Ethernet devices. In addition to general xilinx properties + listed above, nodes for these devices should include a phy-handle + property, and may include other common network device properties + like local-mac-address. + + iv) Xilinx Uartlite + + Xilinx uartlite devices are simple fixed speed serial ports. + + Required properties: + - current-speed : Baud rate of uartlite + + v) Xilinx hwicap + + Xilinx hwicap devices provide access to the configuration logic + of the FPGA through the Internal Configuration Access Port + (ICAP). The ICAP enables partial reconfiguration of the FPGA, + readback of the configuration information, and some control over + 'warm boots' of the FPGA fabric. + + Required properties: + - xlnx,family : The family of the FPGA, necessary since the + capabilities of the underlying ICAP hardware + differ between different families. May be + 'virtex2p', 'virtex4', or 'virtex5'. + - compatible : should contain "xlnx,xps-hwicap-1.00.a" or + "xlnx,opb-hwicap-1.00.b". + + vi) Xilinx Uart 16550 + + Xilinx UART 16550 devices are very similar to the NS16550 but with + different register spacing and an offset from the base address. + + Required properties: + - clock-frequency : Frequency of the clock input + - reg-offset : A value of 3 is required + - reg-shift : A value of 2 is required + + vii) Xilinx USB Host controller + + The Xilinx USB host controller is EHCI compatible but with a different + base address for the EHCI registers, and it is always a big-endian + USB Host controller. The hardware can be configured as high speed only, + or high speed/full speed hybrid. + + Required properties: + - xlnx,support-usb-fs: A value 0 means the core is built as high speed + only. A value 1 means the core also supports + full speed devices. + |